Centrifugal hydroextractor

ABSTRACT

A continuous hydroextractor, for fibrous material, having a rotating frustum cone basket and a distributor of the material rotating with a different speed internally to the said basket. At least one rotating disc fixed to the distributor, having on its edge openings for the exit of the centrifuged material; the disc defining with the basket an annular gap for the exit of the liquid centrifuged, and a perforated filter band for the water placed superiorly and rotating with the abovementioned basket.

United States Patent 11 1 1111 3,920,

Lega et a1. 1451 Nov. 18, 1975 [5 1 CENTRIFUGAL HYDROEXTRACTOR 1.4153939 5/1922 Mabry 1. 23 3/2 1,887,955 11/1932 Reese et a1 [75] Inventom Berla'fdo Lega G'annang'oh 3,647.135 3/1972 Mercier 2 233/2 x Cecchl, both f Florence Italy 374L465 6/1973 Lincoln 233/7 [73] Assignee: Texfluid S.a.s.(Entire), Florence,

Italy Primary Examiner-Ge0rge H. Krizmamch Attorney, Agent, or FirmClarence A. O'Brien; Flled. l0, H ey J obson {21] Appl. No 487,254

1 1 ABSTRACT [30] Foreign Application Priority Data A continuous hydroextractor, for fibrous material,

July 26, 1973 ltaly 27124 having a rotating frusmm cone basket and a distributor of the material rotating with a different speed in- 52 us. (:1. 233/2; 233/7; 233/46 Iema'ly to the Said basket At least one rotating disc In. CLL" 04 1 20; 045 0 30 fixed t0 the distributor, having on its edge openings [5 Fidd f Search u 233/2 3, 7 21, 27, 28 for the exit of the centrifuged material; the disc defin- 233/46 7 R R, 20 A ing with the basket an annular gap for the exit of the liquid centrifuged, and a perforated filter band fer the water placed superiorly and rotating with the above- [56] References Cited UNITED STATES PATENTS menmned basket- 1 231,420 6/1917 Palmer 233/21 12 Claims, 3 Drawing Figures r 30 f l o o o I 25 Z? [1 u {I U.S. Patent Nov. 18, 1975 Sheet 1 of2 3,920,181

U.S. Patent Nov. 18, 1975 Sheet 2 of2 3,920,181

CENTRIFUGAL HYDROEXTRACTOR The present invention refers to a continuously operating centrifugal hydroextractor, particularly adapted for treating fibrous materials such as natural and artificial textile staples.

Continuously operating centrifugal hydroextractors are in general known, it is, however, difficult to use them for the centrifugation of fibrous materials, in as much as their geometrical form and the disposition of the rotating organs of the machine are such as to impede or obstruct the free passage of the fibrous material being fed in, further to this the material to be centrifuged is not kept in the machine for a pre-established or sufficient period of time so as to obtain the desired degree of dehydration.

On the other hand, from a previous patent a continuously operating hydroextractor for fibrous material is known, which resolves the abovementioned problems; substantially such a hydroextractor is made of a rotating frusto-conical perforated basket and contains a member which distributes the material to be centrifuged which rotates at a different speed from that of the basket. The said distributing member substantially comprises blades having surfaces which guide the material from a central feed point towards'the internal peripheral surface of the perforated basket, and which bear at least one disc placed perpendicularly to the axis of rotation of the basket, and which closes this latter on its upper edge. Said disc has along its peripheral edge two or more openings for the exit of the material, each one separated at an angle from the edge of the relative blade to allow the exit of the centrifuged material towards a collecting chamber placed above.

However, with the type of hydroextractor described above, it is in practice possible to have problems of contamination in the treatment of materials which are different to one another and of different colours. In fact, the perforation of the basket causes the retention of fibres in the single holes which can. contaminate the materials successively treated. This problem is particularly acute due to the fact that the filtering area of the basket is below the disc and is difficult to reach for cleaning, unless the machine is stopped and successively dismantled for long. periods of time. A further problem to be resolved is that relative to the deterioration of the fibres of the material treated. lnfact, owing to the variability of thelengths of the fibres oftextile materials to be treated, these fibres undergo deterioration when they are pulled in such a way as to tear or undo them with respect to the whole "flock" which they make up.

This and other problems inherent to the centrifugation of fibrous materials have been resolved with the hydroextractor according to the invention.

In general according to the invention a continuously working hydroextractor for fibrous materials, of the type comprising a rotating frusto-conical basket having an upper circumference edge, and a distributing means for the material rotating at a speed different to that of the basket, placed coaxially and internally of the basket itself, said distributing member comprising blades defining guide surfaces for the material, from a central feed point towards the internal peripheral surface of the above-mentioned basket, and at least one disc perpendicular to the rotation axis of the basket, which is fixed to the abovementioned distributing member to rotate with it, said disc having on its external peripheral edge apertures for the exit ofthe material to be treated, with each opening. which is angularly distant from the edge of the relative blade, said basket having an upper perforated filtering band, and said disc being below as in backward axial position with respect to the said filtering band.

With the solution proposed above it is possible to make the basket with the part below the disc having a completely smooth wall, that is not perforated in such a way as to avoid an accumulation in the holes of resi dues or of fibres of materials already treated, thus resolving the problem of contamination. furthermore, by this solution, the filtering area of the basket, prevalentely made of a perforated metallic band above the disc, is easily accessible from the outside for cleaning, for example by an opposite window out into the upper part of the gatherer casing for collecting the material which is above the basket itself.

With the apparatus proposed, since the disc is at a certain distance from the upper edge of the cylindrical basket, it derives that from the exit point of the material (openings on the disc), to the end part or upper edge of the basket, there is such a distance as to permit the fibres to totally rest, a part on the extension of the non-perforated surface of the basket above the disc, and a part on the filtering area or surface, so as not to create tensions and therefore breakages of the flock during the phase in which the flock itself, or the fibrous material, leaves the basket to then be sent towards the discharge exit of the apparatus. Obviously. the same condition would not occur if the disc were at the same height as the upper edge of the basket, because, in that case, as the material left the disc, it would be dismembered due to the centrifugal force which would force it to tear away from that part of the flock still inside the machine and held by the disc.

According to a form of realization of the invention the solution adopted consisting of having the filtering surface on a frustum cone band of steel plate, perforated, net-like or of other filtering material, fixed releasably to the basket itself, further to being necessary for construction reasons, which permit the rapid changeover of the filter band itself, is also dictated by the necessity of directing the liquid extracted towards the filtering surface at a certain impact angle. In fact, if the filtering surface were in the plane or the extension of the surface of the basket, the liquid extracted which has passed across the gap existing between the disc and the said basket, would encounter the filtering surface in a tangential direction, that is without any variation in direction in the radial sense. Instead with the solution adopted in which a step has been formed with a differently inclined surface, in correspondence with the lower edge of the filtering band, the liquid extracted undergoes a variation in direction towards the filtering band. Moreover, giving a pre-established angle, which is preferably near to in correspondence with the meeting line with the filtering surface, better penetration conditions of the liquid across the same filtering surface are obtained.

Finally, it is to be noted that the use of suitable deflectors, fixed to the disc and placed in the area in which the maximum quantity ofliquid extracted passes, make it possible to avoid that by ventilation or any other cause, part of the liquid sent towards the filtering surface breaks up into mist or small drops, which in that case would deposit on the material already centri- 3 fuged, thus increasing the relative degree of humidity obtainable by the centrifugation.

The invention will be more fully described hereunder with reference to the figures in the enclosed drawings, in which:

FIG. I represents a vertical cross-section ofa centrifugal hydroextractor according to the invention;

FIG. 2 represents a partially broken plan view from the top;

FIG. 3 represents a schematic plan view, on a smaller scale of FIG. 2 without the disc valve, to better show the disposition of the blades of the rotating distributor.

As can be seen from FIGS. 1, 2 and 3, the hydroextractor substantially comprises a circular vat 10, internally of which there is a frustum cone basket 11, supported and rotated by means ofa hollow shaft 12. lnternally of the rotating backet 11, supported by a shaft 12', there is a rotating distributor, indicated as a whole by [3, and this latter has a base 14 onto which the material to be centrifuged falls, centrally fed by an upper hopper l5.

Said rotating distributor l3 comprises two or more blades l6 which extend in opposite radial directions and with their curved 16' serve to send on and guide the fibrous material towards the internal surface of the basket in function of the different rotation speeds at which the distributor l3 and the basket 11 are made to rotate. If desired, each blade 16, may have a curved surface 17, such as to form a gap with the internal surface of the basket which increases the direction contrary to that of the relative motion of the distributor with respect to the basket, as well as a posterior deflecting element 18, which facilitates the exit of the material in the discharge stage and impedes the material from inserting itself between the basket and a blade.

Above the blades 16 and rotating with them, as shown in FIG. 1, the rotating distributor l3 bears a disc 19, fixed to the structure of the distributor by means of the tie rods 20. The disc 19, has, in the case illustrated. two diametrically opposed openings 21, for the exit of the material, the said openings are spaced angularly with respect to the edge 13' of the respective blade 16, as can be clearly understood from the plan view in FIG. 2. The functions of the distributors and of the disc will be understood hereinafter with reference to the description of the working of the machine.

Returning to FIG. I of the drawings, it is to be noted how the disc 19, which is placed perpendicularly to the axis of rotation of the basket and the distributor 13, is disposed below the upper edge of the basket itself and below a filtering perforated band 22 formed or fixed in correspondence with the upper edge of the basket. The basket 11 under the disc 19 preferably has a smooth surface, that is, is not perforated, which continues for a certain tract beyond the disc 19, up to the formation of a small step or surfacedifferently inclined, 23, placed in correspondence with the lower edge of the filtering band 22 previously mentioned. As already remembered. the said small step 23 serves to change the direction of the liquid extracted from the fibrous material which, due to the centrifugal force, runs along the frustum cone internal surface of the basket ll, after having crossed the annular gap, formed between the external circumferential edge of the valve and the disc 19 and the internal surface of the basket ll. goes towards the filtering area or band 22, with an impact angle with respect to the latter, which must preferably be as near as possible to 90.

The filtering band 22, which substantially constitutes an extension of the basket ll, both for construction reasons which require its rapid substitution, as well as for the formation of the step 23, previously mentioned. is made of a band of perforated steel plate or of metal netting, which is suitably fixed by means of screws or nuts 24, in correspondence with the step 23 on the r0- tation basket 11, as previously mentioned. A ring 25 is placed above the filtering band 22 to form an annular edge slightly jutting towards the inside. which impedes the residual water from continuing its run towards a gatherer 26 above the basket 11, into which the material centrifuged is pushed and sent towards the side exit 27. The liquid which exits from the basket through the filtering band 22 gathers in the vat l0, from which it is outwardly discharged through a siphon 29, which allow a smooth flow.

A window 30, placed on the framework of the gatherer 26, allows easy inspection of the filtering band 22 of the previously mentioned basket.

From FIG. 2 of the enclosed drawings and on the right hand side of FIG. 1 it can be seen that along the external peripheral edge of the disc 19, there have been placed deflectors 28. Said deflectors 28 are placed along the circle of an are behind, or downstream of each opening 2] for the exit of the material (with reference to the relative movement of the disc 19) and which corresponds to the area in which there is the passage of the greatest quantity of liquid extracted from the fibrous material across the annular gap existing between the edge of the disc 19 itself, and the internal surface of the basket 11, the deflectors 28, in rubber for example or any other flexible or rigid material, send the flow of liquid towards the filtering area 22 of the basket ll, avoiding the formation of mist or of small drops due to the effect of the strong ventilation existing inside the machine, which otherwise would be deposited on the material already centrifuged exiting from the opening 21. Alternatively, the deflectors could be made of a single flexible deflector element placed above and along the whole peripheral edge of the disc 19.

We will now describe the working of the machine referring to the figures in the enclosed drawings. As said, the basket ll the disc 19 and the rotating distributor 13 with the blades, through their shafts 12 and 12' respectively, joined to a suitable drive (not shown) are made to rotate, for example, in an anti-clockwise direction, at speeds different to one another. Let it be supposed, for example, that the blades and disc rotate at a speed of 9l9.4 rpm. and that the basket rotates at a speed of 920 r.p.m.; for the reasons given above it can be said that the relativemotion of the blades and disc with respect to the basket is a rotation of 0.6 r.p.m.; in a clockwise direction.

This being premised the material which arrives through the storage hopper ]5 on the bottom of the distributor, is considered. Thanks to the action of the centrifugal force. the material is sent by the blades 16 onto the internal surface of the basket 11. Since the basket wall has a greater slope at the friction angle of any flbrous material to be treated, the material rises along the internal surface of the basket but cannot exit from the said basket because it is held in by the disc 19. It is clear that what has been said here is also valid in the case in which the machine has two or more discs in a series, that is to say with discs placed above one another, solidly fixed to the distributor, with the disc openings suitably dephased. as long as the last disc. the upper one or the one nearest to the edge of the basket. is always slighly below the filtering band. as has been said for the disc l9 in the example illustrated.

The material is thus placed between the internal surface of the basket and the lower surface of the disc. in this position the material is very adherent to the inter nal surface of the basket. due to the centrifugal force and is not at all adherent to the lower surface of the disc. For this reason the material still remains in the basket while the disc slides above the material since this latter rotated with a rotating movement of 0.6 r.p.m. with respect to the basket itself.

As stated the disc has apertures along its external edge; therefore the exit of the material from the basket occurs when the said apertures of the disc are above the material.

The amount of time spent by the material inside the basket is constant, and is determined by the relative motion between the disc 19 and the basket 11, as well as the constant angular distance between the edge 13' of the blade with respect to the opening 21 which follows it.

The material which exits through the openings ofthe disc, as said previously. comes to rest on the upper extension of the basket and above the filter band 22, after leaving this latter it is sent towards the cylindrical gatherer 26. From this latter, thanks to the speed of the material itself and to the air current created by the rotation of the blades and discs, the material is discharged towards the outside through the exit-mouth 27.

What has been described herein clarifies the movement of the material inside the machine, while as regards the hydroextraction of the material. this occurs during the period in which the material remains inside the machine. that is when the material is subject to the action of the centrifugal force. Still referring to the drawings, during this period the liquid extracted from the material rises along the internal surface of the frustum cone basket. until it meets the perforated frustum cone band 22 made of metal netting or of perforated steel plate, Therefore the liquid passing through the said perforated net or steel plate is sent to the collection tank and from there discharged through the siphon 29.

From what has been said above it can be noted that the frustum cone basket has no perforations inside or underneath the disc, since, inevitably they would detain small flocks or fibres of material and thus there would be the possibility of contamination (in the case of a change in the type and/or the colour of the material), of the material to be successively treated. Obviously the annular gap between the disc and the internal surface of the basket is of such a dimension as to permit the passage of the liquid extracted but not the passage of the material. The liquid which exits through the said annular gap is sent. both by the action of the step 23 and by the deflectors 28, which with their peripheral edge brush on the perforated edge 22, towards the per' forated edge itself this avoids small quantities of liquid 6 being detached from the basket by means of ventilation and returning to dampen the material already centrifuged before exiting from the machine.

We claim:

1. A continuously operating centrifugal hydroextractor of the type comprising a frustum cone rotating basket. and a mechanical distributor rotating at a speed different to that of the basket. placed coaxially internally to this latter. the said mechanical distributor comprising blades to guide the material from a central feedpoint towards the peripheral surface of the said basket. and at least one disc placed perpendicularly to the axis of rotation of the basket, rotating fixedly to the said blades. the said disc having openings on its peripheral edge for the exit of the material, with each opening an gularly spaced from the edge of the relative blade. said disc defining with the internal surface of the basket, an annular gap for the passage of the centrifuged liquid. and that the said basket has on the top a perforated filtering band. the said disc being below the perforated band.

2. A hydroextractor according to claim I. in which said disc is the upper edge of the basket.

3. A hydroextractor according to claim 1, in which said basket has the formation of a step in correspondence with the lower edge of the said filtering band.

4. A hydroextractor according to claim 1. in which the said filtering band is fixed removably to the upper edge of the backet.

5. A hydroextractor according to claim 1, in which the said basket has. underneath the disc. a smooth, imperforate wall.

6. A hydroextractor according to claim 5, in which the said smooth imperforate wall, of the basket continues for a tract beyond the disc to the lower edge of the said filtering band.

7. A' hydroextractor according to claim 3, in which the said step forms a surface. substantially perpendicular to the said filtering band.

8. A hydroextractor according to claim 4, in which the said filtering band is a perforated band in metal plate.

9. A hydroextractor according to claim 4, in which the said filter band is made of netting.

10. A hydroextractor according to claim 1, in which the said disc has, along the gap of passage of the centrifuged liquid. deflecting elements which direct the liquid towards the said filter band.

ll. A hydroextractor according to claim 10, in which the said deflector elements are placed along a tract of the peripheral edge of the disc placed posteriorly to each opening for the exit of the material. with reference to the direction of rotation of said disc with re spect to the rotating basket.

12. A hydroextractor according to claim 10, in which the said deflector elements are made ofa single flexible deflector element placed above and along all the peripheral edge of the disc. 

1. A continuously operating centrifugal hydroextractor of the type comprising a frustum cone rotating basket, and a mechanical distributor rotating at a speed different to that of the basket, placed coaxially internally to this latter, the said mechanical distributor comprising blades to guide the material from a central feed-point towards the peripheral surface of the said basket, and at least one disc placed perpendicularly to the axis of rotation of the basket, rotating fixedly to the said blades, the said disc having openings on its peripheral edge for the exit of the material, with each opening angularly spaced from the edge of the relative blade, said disc defining with the internal surface of the basket, an annular gap for the passage of the centrifuged liquid, and that the said basket has on the top a perforated filtering band, the said disc being below the perforated band.
 2. A hydroextractor according to claim 1, in which said disc is the upper edge of the basket.
 3. A hydroextractor according to claim 1, in which said basket has the formation of a step in correspondence with the lower edge of the said filtering band.
 4. A hydroextractor according to claim 1, in which the said filtering band is fixed removably to the upper edge of the backet.
 5. A hydroextractor according to claim 1, in which the said basket has, underneath the disc, a smooth, imperforate wall.
 6. A hydroextractor according to claim 5, in which the said smooth imperforate wall, of the basket continues for a tract beyond the disc to the lower edge of the said filtering band.
 7. A hydroextractor according to claim 3, in which the said step forms a surface, substantially perpendicular to the said filtering band.
 8. A hydroextractor according to claim 4, in which the said filtering band is a perforated band in metal plate.
 9. A hydroextractor according to claim 4, in which the said filter band is made of netting.
 10. A hydroextractor according to claim 1, in which the said disc has, along the gap of passage of the centrifuged liquid, deflecting elements which direct the liquid towards the said filter band.
 11. A hydroextractor according to claim 10, in which the said deflector elements are placed along a tract of the peripheral edge of the disc placed posteriorly to each opening for the exit of the material, with reference to the direction of rotation of said disc with respect to the rotating basket.
 12. A hydroextractor according to claim 10, in which the said deflector elements are made of a single flexible deflector element placed above and along all the peripheral edge of the disc. 